English: One may not roast the Pesach on a metal spit — because metal, once part of it is hot, is all hot, and the Merciful One said “roasted with fire,” and not roasted by something else.
On the daf / in context: See the cited source for the full section.
Type of Learning
Derash on the verse (Pesachim 74a) — not a formal named middah of the 13.
What Is Learned
The Pesach is not roasted on a metal spit that would cook by the spit’s heat.